Apple undid license restrictions for software developed for iOS devices on Thursday, saying it was taking developer feedback to heart. "We are relaxing all restrictions on the development tools used to create iOS apps, as long as the resulting apps do not download any code," Apple said in a statement.

According to the developer agreement (PDF), Apple removed the extra words it had added to section 3.3.1 of that license in April that blocked the Flash-derived apps: "Applications must be originally written in Objective-C, C, C++, or JavaScript as executed by the iPhone OS WebKit engine, and only code written in C, C++, and Objective-C may compile and directly link against the Documented APIs (e.g., Applications that link to Documented APIs [application programming interfaces] through an intermediary translation or compatibility layer or tool are prohibited)."

Adobe, the major company affected by this change, was cautiously optimistic. "We are encouraged to see Apple lifting its restrictions on its licensing terms, giving developers the freedom to choose what tools they use to develop applications for Apple devices," the company said in a statement. And the stock market was quick to take notice of the change in fortunes, pushing Adobe shares up about 12 percent in morning trading.

What comes next for Adobe is somewhat unclear, but it seems at a minimum that Flash-derived applications will stand on their own merits according to how well they work, not their programming origins.

And Apple, with its control over the App Store distribution channel, still has plenty of leeway to bar what it doesn't like case by case. According to the new App Store Review Guidelines also released Thursday, "If your app doesn't do something useful or provide some form of lasting entertainment, it may not be accepted...We have lots of serious developers who don't want their quality apps to be surrounded by amateur hour."

Some developers besides Adobe weren't happy with Apple's move in April. Jonathan "Wolf" Rentzsch was so discouraged by the situation concerning Apple's section 3.3.1 that in May he canceled a Mac developer conference as a result.

Unity Technologies, which sells cross-platform developer tools to let programmers reach iOS and other devices, also came under a cloud in April, when Apple changed its policy. Although new Unity-created apps have continued to arrive in the App Store since then, Unity co-founder Nicholas Francis evidently was happy to see Apple's policy changed.

"We applaud this move by Apple. We are all about enabling people to work with the best tools for any given job. Apple has always been focused on providing superior products to end users," Francis said. "Unity games have been continuously released throughout this period. However, we are very happy for all those developers who can now join the party."

Another company in the same boat as Unity, Appcelerator, argued that Apple's move was wise because it helps foster developer innovation, strengthens Apple's iOS advantage in the long run, and ultimately "benefits consumers as the ultimate arbiters of quality in the App Store," the company said in a statement. "We're incredibly pleased with this morning's announcement," said Chief Executive Jeff Haynie. More than 4,000 iPhone and Android applications were built with Appcelerator.

Apple didn't immediately respond to requests for comment. But one thing is clear: Adobe didn't come to its decision to scrap its Flash-to-iOS project lightly, and resurrecting it wouldn't be simple. Programmers would need to be retrieved from new projects, and resources would need to be reallocated for marketing, support, and developer relations to some degree.

Adobe released the tool, part of Flash Professional CS5, at about the same time Apple released the iPad earlier this year. That's when the difference between the companies escalated to a very public battle.

Adobe fought back with an ad campaign that asserted, "We love Apple," but it added, "What we don't love is anybody taking away your freedom to choose what you create, how you create it, and what you experience on the Web."

In addition, Adobe loudly allied with Google, whose Android operating system is iOS' most direct competitor. New Android phones and tablets can run Flash Player 10.1, at least in theory letting owners of those devices tap into Flash-based Web sites, games, and applications that iOS users can't. Many Flash developers didn't create their projects with small touch-screen interfaces and feeble mobile-phone processors in mind, but some of those constraints are easing as mobile-device hardware gets steadily more powerful.